1. Field of the Invention
The present invention relates to improvements in or relating to a desuperheater for controllable injection of cooling water in a steam or gas line, where the desuperheater heater includes an insertion tube extending into the line and having a conical outlet nozzle, in the nozzle there being a valve body movably disposed in an aperture such as to form a regulating port.
1. Description of the Related Art
Such superheater devices, particularly for steam, are customarily used for cooling and/or regulating steam temperatures. These devices often comprise an injection nozzle provided with a single-seat means regulating the degree of opening, for increasing the cooling water speed at the nozzle outlet. The injected cooling water will thus be forced out in a thin, conically shaped jet consisting of extremely small water droplets, which evaporate almost immediately. There are many fields of use, but the majority of installations where these devices are used can usually be put into one of the following classes of general and industrial standard installations: power stations which, apart from the high pressure and the high temperature side, also produce steam for auxiliary machines, heating systems and tap stations; with surface heat exchangers for better heat transfer; on boilers, either between the super heating steps or for regulating the partial load steam temperature; cooling of superheated steam for adjusting the steam temperature to an industrial process; anywhere where the process or scrubbing steam is required in the low pressure system in process industries and refineries; or a district heating plant.
An interesting application, not included in the use in connection with steam, is cooling a gas by injecting it in its liquid phase.
A known type of desuperheater device of the kind in question is illustrated in the Swedish Patent Specification SE 6613074, relating to a steam desuperheater which includes an insertion tube which can be mounted at 60.degree.-45.degree. to the pipeline in which the cooled medium flows. This tube includes in turn a cylindrical valve body for regulating the cooling water by uncovering tangentially bored holes in a tube inside the insertion tube. Such a solution signifies that the cooling water forms a cone at the end of the insertion tube inside the line in question. With the method of installation demanded by older types of desuperheaters, and which is also required for the previously known application just mentioned, there is under certain conditions an obvious risk that unvaporized water droplets can reach the opposing pipe wall and cause damage in the form of erosion.